The number of channels and/or services offered or available is increasing from hundreds to tens of thousands. Providers are increasingly attempting to consolidate the number of network elements needed to provide services. As a result, fewer devices may support a far greater number of services. In providing such services, encryption and decryption techniques may be implemented to prevent unauthorized access to the services.
The Digital Video Broadcasting (DVB) standard, ETSI TS 103 197 v1.5.1 (2008-10) offers a technique for producing and consuming a control word and associated entitlement control message (ECM) for one cryptographic period (also referred to herein as a crypto period) at a time. A control word may be a secret key that may be used to scramble a clear media stream at an encryption device such as, for example, an Encryptor, an Edge Quadrature Amplitude Modulation modulator (EQAM) with an embedded encryptor, a Converged Cable Access Platform (CCAP) device with an embedded encryptor, computer, and/or other computing device, and to descramble a scrambled media stream (e.g., a channel) at a receiver device such as, for example, a set-top box, computer, tablet, and/or other computing device.
As a result, once a network element (e.g., a scrambler) inserts an ECM for one cryptographic period into a media stream, the network element may communicate with generator of the control words and the generator of the ECMs to obtain the next control word and ECM for the next cryptographic period. As a result of retrieving control words and associated ECMs on a per cryptographic period basis and because a cryptographic period typically may be a few seconds in length, the network elements may frequently communicate with the generators resulting in inefficient bandwidth usage across the network. Additionally, the cryptographic period may be set to a longer timeframe than is desired to account for latency in retrieval of the next control word and associated ECM from the generators. For example, the latency time may include the time taken to send a request for the next control word and associated ECM from the scrambler to the generators, the time the generators take to create the next control word and associated ECM, and the time taken for the scrambler to receive the next control word and associated ECM. Furthermore, the frequent retrieval of the control words and associated ECMs impedes scaling consolidated systems to support thousands of services. These and other shortcomings are addressed by the disclosure.